* fix(terminal): raise SSH flow high-water mark to stop WAN pause ping-pong (#1961)
Bulk terminal output over SSH (e.g. `tail -2000f big.log`) was far slower
than other clients on high-latency links. The renderer's output flow control
pauses the source stream once its unacked backlog crosses FLOW_HIGH_WATER_MARK
(previously 100KB). For SSH the source is the ssh2 channel, so pause() stops
the remote until resume() plus a full round-trip.
ssh2's own channel window is 2MB (WINDOW_THRESHOLD 1MB), so a 100KB watermark
made Netcatty pause/resume dozens of times during a multi-MB dump — a 4MB dump
triggered ~61 pause cycles, each costing ~1 RTT. At 300ms RTT that turned a
~2s dump into ~21s.
Raise FLOW_HIGH_WATER_MARK to 1MB so it sits near the ssh2 window; the same
4MB dump now settles in ~4 pause cycles (~2-3s at 300ms RTT) while still
bounding renderer memory. FLOW_LOW_WATER_MARK stays at 8KB to keep interactive
acks responsive.
Co-authored-by: Cursor <cursoragent@cursor.com>
* test(terminal): align deferred-ack test with 1MB flow high-water mark
The deferred IPC ack batch threshold (XTERM_WRITE_CALLBACK_BATCH_BYTES)
now sits far below FLOW_HIGH_WATER_MARK, so deferral alone can no longer
accumulate up to the watermark. Assert the batch-flush invariant instead.
Co-authored-by: Cursor <cursoragent@cursor.com>
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Co-authored-by: Cursor <cursoragent@cursor.com>
陈大猫
476e441057